Button fastener



FIG. 1 is an exploded perspective view of a button fastener showing mynew design, the broken line showing of a button is for illustrativepurposes only and forms no part of the claimed design;

FIG. 2 is a side view thereof;

FIG. 3 is a top view thereof;

FIG. 4 is a bottom view thereof; and,

FIG. 5 is a perspective view of the button mounting assembly with thetwo mounting portions assembled together.

The ornamental design for a button fastener, as shown and described.